Pressure question from a newbe....

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by SMF, Sep 28, 2012.

  1. SMF

    SMF Member

    Messages:
    17
    Joined:
    Apr 14, 2011
    Okay here's where I am.... I'm working up a load for the new Barrnes LRX BT 173 grain .308. I've arrived at what I think is am accurate recipe. At 100 meters, I am making a single ragged hole. I do however have two questions: Is a 27 fps average spread with an average velocity of 2712.5 fps acceptable for longer ranges (500 to 800 meters)? Also my primers aren't flattening at all, but there is slight cratering on the firing pin impact point. Is this a sign of unacceptably high pressures? I'm seating the bullet 0.05” off the lands. The load is in R-P brass, 42.5 grains of Varget infront of a CCI BR-2 primer. Any input would be helpful. Thank you.

    Steve gun)
     
  2. Lefty7mmstw

    Lefty7mmstw Well-Known Member

    Messages:
    4,280
    Joined:
    May 13, 2012
    Sounds rather normal to me. If your rifle is a rem of recent build, a loose firing pin hole is rather normal and will cause a bit of crater with all but start charges. Other makes and I'd make sure factories aren't cratering before I'd be satisfied with my pressures.
     

  3. SMF

    SMF Member

    Messages:
    17
    Joined:
    Apr 14, 2011
    Thank you for your reply. I take it that you are a lefty too? The rifle is a new Savage F10LCP. I'm really happy with the accuracy with this recipe I was just a little concerned about the cratering. My Remington 700 300 RUM does that too with just about any load I feed it. I live in the mountains of extreme northern California and there aren't any 500 yard/meter ranges within 100 miles. I travel into the central valley where there is a 500 yard range every couple of months. I'm planning of making a stop there in a few weeks. We are limited to about 200 meters this time of year due to fire danger. I the wetter months we can shoot out to around 700 meters but it’s a 13 degree up hill shot...

    Steve
     
  4. Lefty7mmstw

    Lefty7mmstw Well-Known Member

    Messages:
    4,280
    Joined:
    May 13, 2012
    Yep, just became a lefty yesterday when I shot my right hand off.
    Just kidding, but I also have a 300 rum in a lh rem and it is a heck of a rifle. I haven't shot a standard 30 in years, excepting a week long fling with a savage axis/edge 30-06, before I got smart and gave it back towards another rifle. I do shoot a savage striker in 22-250 and like it, but the edge was a rather sorry rifle.
     
  5. 4bycamper

    4bycamper Well-Known Member

    Messages:
    607
    Joined:
    Apr 11, 2009
    This all sounds like the usual stuff to me. My 7 saum and my 270 wsm both raise primer cratering on fired cases. I can feel the size of the crater with my thumb nail. If it gets too big I can always back off the charge a little. Enjoy gun)
     
  6. SMF

    SMF Member

    Messages:
    17
    Joined:
    Apr 14, 2011
    Thank you for your input gentlemen. I usually lurk here, not wanting to bother folks, but I thought I'd jump in and ask. BTW: I had a muzzle break installed on my 300 RUM and it's a joy to shoot now even with 208 grain bullets at 3150 fps. Heck, I like it so much, I'm considering having a muzzle break installed on my 45-70 too. I'm a pig hunter and most of my hunting is done at only 400 to 600 meters. There's just something magical about shooting little groups on paper or metal that's a long ways away that has started me chasing the dragon.

    Thanks again!

    Steve
     
  7. Lefty7mmstw

    Lefty7mmstw Well-Known Member

    Messages:
    4,280
    Joined:
    May 13, 2012
    Lower pressure rounds aren't going to see the same improvement with a muzzle break. You should weigh the fact that your recoil reduction % will be less than the ultra's was before you decide to drop the cash on it for the 45-70.
     
  8. SMF

    SMF Member

    Messages:
    17
    Joined:
    Apr 14, 2011
    Thank you! I didn't realize that. As I said, I'm kind of a newbie. My 45-70 isn’t all that bad, I saw such a dramatic reduction in felt recoil in my 300 RUM, I assumed that It would be a real change in the felt recoil on the 45-70 as well. I'd rather spend the money on reloading supplies and such anyway.
     
  9. SMF

    SMF Member

    Messages:
    17
    Joined:
    Apr 14, 2011
    Thank you! I didn't realize that. As I said, I'm kind of a newbie. My 45-70 isn’t all that bad, I saw such a dramatic reduction in felt recoil in my 300 RUM, I assumed that It would be a real change in the felt recoil on the 45-70 as well. I'd rather spend the money on reloading supplies and such anyway.

    Steve gun)